Abstract： Objective To study the relationship between polymorphisms of transforming growth factor β1 gene and endothelin converting enzyme-1b gene and susceptibility of carotid atherosclerosis. Methods Two hundred and thirty-one patients with carotid atherosclerosis, admitted to and received treatment in our hospital from January 2006 to December 2010, and 231 healthy volunteers were chosen in our study. The polymorphisms of transforming growth factor β1 gene and endothelin converting enzyme-lb gene in these 2 groups were detected with PCR and single nucleotide polymorphism; the differences of these gene and genotype between the 2 groups were compared by statistical analysis.Results The gene and genotype of transforming growth factor β1 gene at rs51695112 locus were significantly different between patient group and control group (x2=6.120, 6.890;P=0.045, 0.033, respectively); the G allele and G/G genotype were risk factors of carotid atherosclerosis susceptibility (OR=1.320, 1.410, respectively). The gene and genotype of endothelin converting enzyme-1b gene at rs32570233 locus were significantly different between the patient group and the control group (x2=6.320, 7.180; P=0.041, 0.022); the A allele and A/A genotype were the risk factors of carotid atherosclerosis susceptibility (OR=1.470, 1.530, respectively). Conclusion There is an association between polymorphisms of transforming growth factor β 1 gene and endothelin converting enzyme-1b gene and carotid atherosclerosis.